Regioselective Fries Rearrangement and Friedel−Crafts Acylation as Efficient Routes to Novel Enantiomerically Enrichedortho-Acylhydroxy[2.2]paracyclophanes
作者:Valeria Rozenberg、Tat’yana Danilova、Elena Sergeeva、Evgenii Vorontsov、Zoya Starikova、Konstantin Lysenko、Yuri Belokon’
DOI:10.1002/1099-0690(200010)2000:19<3295::aid-ejoc3295>3.0.co;2-0
日期:2000.10
Two useful approaches to ortho-acylhydroxy[2.2]paracyclophanes, starting from 4-hydroxy[2.2]paracyclophane, have been developed. TiCl4-catalyzed Fries rearrangement and direct acylation occur regioselectively (to the ortho position with respect to the hydroxy group), leading to 4-acetyl-5-hydroxy[2.2]paracyclophane (3) and 4-benzoyl-5-hydroxy[2.2]paracyclophane (4) in high to excellent chemical yields
从 4-羟基 [2.2] 对环烷开始,已经开发出两种有用的邻酰基羟基 [2.2] 对环烷方法。TiCl4 催化的 Fries 重排和直接酰化发生区域选择性(相对于羟基的邻位),导致 4-乙酰基-5-羟基 [2.2] 对环烷 (3) 和 4-苯甲酰基-5-羟基 [2.2]对环芳烷 (4) 具有高至优异的化学产率。对于化合物 4,已进行 X 射线研究。邻酰基羟基[2.2] 对环芳烃 3 和 4 以富含对映异构体的形式(ee 92-99%)获得,并且它们的对映异构体的绝对构型已经确定。